ceph/doc/rados/troubleshooting/cpu-profiling.rst
Zac Dover 513c436aef doc/troubleshooting: edit cpu-profiling.rst
Improve the language in the "oprofile" section of the RADOS
Troubleshooting Guide.

Signed-off-by: Zac Dover <zac.dover@proton.me>
2023-08-13 16:55:55 +10:00

81 lines
1.7 KiB
ReStructuredText

===============
CPU Profiling
===============
If you built Ceph from source and compiled Ceph for use with `oprofile`_
you can profile Ceph's CPU usage. See `Installing Oprofile`_ for details.
Initializing oprofile
=====================
``oprofile`` must be initalized the first time it is used. Locate the
``vmlinux`` image that corresponds to the kernel you are running:
.. prompt:: bash $
ls /boot
sudo opcontrol --init
sudo opcontrol --setup --vmlinux={path-to-image} --separate=library --callgraph=6
Starting oprofile
=================
Run the following command to start ``oprofile``:
.. prompt:: bash $
opcontrol --start
Stopping oprofile
=================
Run the following command to stop ``oprofile``:
.. prompt:: bash $
opcontrol --stop
Retrieving oprofile Results
===========================
Run the following command to retrieve the top ``cmon`` results:
.. prompt:: bash $
opreport -gal ./cmon | less
Run the following command to retrieve the top ``cmon`` results, with call
graphs attached:
.. prompt:: bash $
opreport -cal ./cmon | less
.. important:: After you have reviewed the results, reset ``oprofile`` before
running it again. The act of resetting ``oprofile`` removes data from the
session directory.
Resetting oprofile
==================
Run the following command to reset ``oprofile``:
.. prompt:: bash $
sudo opcontrol --reset
.. important:: Reset ``oprofile`` after analyzing data. This ensures that
results from prior tests do not get mixed in with the results of the current
test.
.. _oprofile: http://oprofile.sourceforge.net/about/
.. _Installing Oprofile: ../../../dev/cpu-profiler